Portion of tread of a tire



FIG. 1 is a front side perspective view of one embodiment of a portion of tread of a tire; and,

FIG. 2 is an enlarged fragmentary front elevational view of portion of the tread shown in FIG. 1.

The broken lines depict environmental subject matter only and form no part of the claimed design. The dash-dot-dot-dash lines define the boundary of the claim but form no part thereof. 

I claim the ornamental design for a portion of tread of a tire, as shown and described. 